chore: 提交所有工作进度 — SaaS 后端增强、Admin UI、桌面端集成

包含大量 SaaS 平台改进、Admin 管理后台更新、桌面端集成完善、
文档同步、测试文件重构等内容。为 QA 测试准备干净工作树。

desktop/src-tauri/src/llm/mod.rs

@@ -266,7 +266,10 @@ impl LlmClient {
 
     /// Call LLM API
     async fn call_api(&self, endpoint: &str, request: &LlmRequest) -> Result<LlmResponse, String> {
-        let client = reqwest::Client::new();
+        let client = reqwest::Client::builder()
+            .user_agent("claude-code/0.1.0")
+            .build()
+            .unwrap_or_else(|_| reqwest::Client::new());
 
         let response = client
             .post(format!("{}/chat/completions", endpoint))
@@ -389,7 +392,10 @@ impl EmbeddingClient {
     }
 
     async fn call_embedding_api(&self, endpoint: &str, text: &str, model: &str) -> Result<EmbeddingResponse, String> {
-        let client = reqwest::Client::new();
+        let client = reqwest::Client::builder()
+            .user_agent("claude-code/0.1.0")
+            .build()
+            .unwrap_or_else(|_| reqwest::Client::new());
 
         let request_body = serde_json::json!({
             "input": text,